Ion implanters are widely used in semiconductor manufacturing to selectively alter conductivity of materials. In a typical ion implanter, ions generated from an ion source are directed through a series of beam-line components that may include one or more analyzing magnets and a plurality of electrodes. The analyzing magnets select desired ion species, filter out contaminant species and ions having undesirable energies, and adjust ion beam quality at a target wafer. Suitably shaped electrodes may modify the energy and the shape of an ion beam.
FIG. 1 shows a conventional ion implanter 100 which comprises an ion source 102, extraction electrodes 104, a 90° magnet analyzer 106, a first deceleration (D1) stage 108, a 700 magnet analyzer 110, and a second deceleration (D2) stage 112. The D1 and D2 deceleration stages (also known as “deceleration lenses”) are each comprised of multiple electrodes with a defined aperture to allow an ion beam to pass therethrough. By applying different combinations of voltage potentials to the multiple electrodes, the D1 and D2 deceleration lenses can manipulate ion energies and cause the ion beam to hit a target wafer at a desired energy.
The above-mentioned D1 or D2 deceleration lenses are typically electrostatic triode (or tetrode) deceleration lenses. FIG. 2 shows a perspective view of a conventional electrostatic triode deceleration lens 200. The electrostatic triode deceleration lens 200 comprises three sets of electrodes: entrance electrodes 202 (also referred to as “terminal electrodes”), suppression electrodes 204 (or “focusing electrodes”), and exit electrodes 206 (also referred to as “ground electrodes” though not necessarily connected to earth ground). A conventional electrostatic tetrode deceleration lens is similar to the electrostatic triode deceleration lens 200, except that a tetrode lens has an additional set of suppression electrodes (or focusing electrodes) between the suppression electrodes 204 and the exit electrodes 206.
In the electrostatic triode deceleration lens 200, each set of electrodes may have a space/gap to allow an ion beam 20 to
In view of the foregoing, it may be understood that there are significant problems and shortcomings associated with current ion implantation technologies.